One sheet of standard OSB, or oriented strand board, weighs approximately 78 pounds. A standard sheet of OSB is 4 feet by 8 feet. OSB is structurally similar to plywood, varying mainly in the manufacturing process.
OSB is manufactured using rectangular wood strands arranged in cross-oriented layers. Plywood is made using thin sheets of veneer that are glued together, with each layer positioned perpendicular to the adjacent layer. The manufacturing process gives OSB a uniform quality that has fewer soft spots than plywood, although both materials are manufactured according to the same performance standards. OSB uses smaller diameter trees and is considered a more environmentally friendly building material.